• Membrane Journal
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• v.24 no.1
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• pp.20-30
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• 2014

A membrane-coupled sequencing batch reactor (MSBR) was used for the advanced treatment of rural village sewage which is very low C/N ratio. The effect of powdered activated carbon, aeration rate, and external organic material loadings on the treatment efficiency and filtration performance were investigated in sequencing batch reactor, in which a flat-sheet type microfiltration membrane with a pore size of $0.4{\mu}m$ was submerged. At the initial operation (within 54 days) MLSS concentration, and the removal efficiencies of COD, T-N, and T-P were increased with the increase of C/N ratio. After 89 days the removal efficiencies of COD, T-N, and T-P were 97.1%, 75.0%, and 48.3%, respectively. Suspended solid-free effluent was obtained by membrane filtration. The T-P removal was relatively low because of depending on the amount of excess sludge wasting. During the operation of MSBR with powdered activated carbon, the particle size of the sludge reduced by the increase of collision frequency and mixing intensity. In comparison with MSBR without powdered activated carbon, TMP of MSBR with that was significantly elevated.

• Particle and aerosol research
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• v.6 no.4
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• pp.173-183
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• 2010

The high temperature pleated filter bags which were used during this study were made of pleated nonwoven fabric of heat and acid resistant polysulfonate fibers which can withstand the heat up to $300^{\circ}C$ and have a filtration area which is 3 to 5 times larger than the conventional round filter bags. Cartridge module packed with 3 kind of the sulfur impregnated activated-carbon based sorbents were inserted in the inner of the pleated filter bag. This type of pleated filter bag was designed to remove not only the particulate matter but also the gaseous elemental mercury. The electrostatic precipitator part can enhance the particulate removal efficiency and reduce the pressure drop of the pleated filter bag by agglomerated particles to form a more porous dust layer on the surface of the pleated bag which is increased the filter bag cleaning efficiency. In addition, the most of particles are separated from the flue gas stream through the cyclone and the electrostatic precipitator part which were installed at the lower part and main body part of the convergence particulate collector, respectively. Thus reduce particulate loading of the high temperature pleated filter bags were applied in this study to analyze the removal characteristics of particulate matter and gaseous elemental mercury.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.773-782
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• 1998

The adsorption experiment of phenol(Ph) from aqueous solution on granular activated carbon was studied in order to design the fixed-bed adsorption column. The experimental data were analyzed by unsteady-state, one-dimensional heterogeneous model. Finite element method(FEM) was applied to analyze the sensitivity of parameter and to predict the fixed-bed adsorption column performance on operation variable changes. The prediction model showed similar effect to mass transfer and intraparticle diffusion coefficient changes suggesting that both parameter present mass transfer rate limits for GAC-phenol system. The Freundlich constants had a greater effect than kinetic parameters for the performance of fixed-bed adsorption column. FEM solution facilitated prediction of concentration history in solution and within adsorbent particle.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.122-127
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• 2006

The aim of this study was to investigate the characteristics of membrane fouling caused by soluble organic materials in a membrane bioreactor process. For the removal of filterable organic materials (FOC) smaller than $1{\mu}m$, coagulants and activated carbon were added. A membrane bioreactor using a submerged $17{\mu}m$ metal sieve was operated in laboratory scale to examine the possibility of membrane fouling control. As the dosage of GAC and coagulant increased, the residual FOC concentration decreased and the permeate flow rate increased markedly. The permeate flux increased with an increased PACl addition at the range from 0 to 50 mg/l. At coagulant dosage of 27mg/l, the removal of FOC was about 46% and the flux increased to 3.5 times compared to the case without PACl addition. The permeate flux increased gradually with an increase in GAC dosage. At GAC dosage of 50mg/L, the permeate flux was about 2 times higher compared that for raw water. The particle in the range of $0.1{\sim}1.0{\mu}m$ were removed effectively by the addition of GAC and coagulant. Higher osage of GAC and coagulant, led to higher removal of FOC. A different set of experiments was also performed to investigate the effect of pretreatment on the permeation ability of MBR system using the metal sieve membrane. After 40 hours of operation, the permeate flux was about 1,000 ($L/m^2-hr$), which is 20 times higher compared to the results in literature. It is likely that combined pretreatment using coagulant and activated carbon was the most effective to resolve membrane fouling problems. Moreover, the continuous operations could be successful by applying this pretreatment method.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.293-298
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• 2016

A hydrogel electrolyte consisting of 6 M KOH aqueous solution, potassium polyacrylate (PAAK, 3 wt.%), and a hydrophilic silica OX50 (1 wt.%) was prepared to use as an electrolyte medium coated on a Scimat separator of activated carbon supercapacitor. The silica particle distributed homogeneously on surface pores of the separator to increase ionic conductivity and electrochemical stability of the hydrogel electrolyte. The silica addition also involved superior specific capacitance even at higher scan rates due to decrease in interfacial resistance between hydrogel electrolyte and activated carbon electrode.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.369-375
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• 2018

Batch experiments were conducted to investigate the effects of operating parameters such as the temperature, initial concentration, contact time and adsorbent dosage on the adsorption of antibiotics amoxicillin (AMX) by waste citrus peel based activated carbon (WCAC). The kinetics and isotherm experiment data can be well described with the pseudo-second order model and the Langmuir isotherm model, respectively. The maximum adsorption capacity of AMX by WCAC calculated from the Langmuir isotherm model was 125 mg/g. The adsorption of AMX by WCAC shows that the film diffusion (external mass transfer) and the intraparticle diffusion occur simultaneously during the adsorption process. The adsorption rate is more influenced by the intraparticle diffusion than that of the external mass transfer as the particle size of WCAC increases, and the intraparticle diffusion is the rate controlling step. The thermodynamic parameters indicated that the adsorption reaction of AMX by WCAC was an endothermic and spontaneous process.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.5
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• pp.399-409
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• 2018

Prussian blue is known as a superior material for selective adsorption of radioactive cesium ions; however, the separation of Prussian blue from aqueous suspension, due to particle size of around several tens of nanometers, is a hurdle that must be overcome. Therefore, this study aims to develop granule type adsorbent material containing Prussian blue in order to selectively adsorb and remove radioactive cesium in water. The surface of granular activated carbon was grafted using a covalent organic polymer (COP-19) in order to enhance Prussian blue immobilization. To maximize the degree of immobilization and minimize subsequent detachment of Prussian blue, several immobilization pathways were evaluated. As a result, the highest cesium adsorption performance was achieved when Prussian blue was synthesized in-situ without solid-liquid separation step during synthesis. The sample obtained under optimal conditions was further analyzed by scanning electron microscope-energy dispersive spectrometry, and it was confirmed that Prussian blue, which is about 9.7% of the total weight, was fixed on the surface of the activated carbon; this level of fixing represented a two-fold improvement compared to before COP-19 modification. In addition, an elution test was carried out to evaluate the stability of Prussian blue. Leaching of Prussian blue and cesium decreased by 1/2 and 1/3, respectively, compared to those levels before modification, showing increased stability due to COP-19 grafting. The Prussian blue based adsorbent material developed in this study is expected to be useful as a decontamination material to mitigate the release of radioactive materials.

• Journal of Powder Materials
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• v.19 no.6
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• pp.424-428
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• 2012

Nano Pd spot-coated active carbon powders were synthesized by a hydrothermal-attachment method (HAA) using PVP capped Pd colloid in a high pressure bomb at $250^{\circ}C$, 450 psi, respectively. The PVP capped Pd colloid was synthesized by the precipitation-redispersion method. PVP capped Pd nano particles showed the narrow size distribution and their particle sizes were less than 8nm in diameter. In the case of nano Pd-spot coated active carbon powders, nano-sized Pd particles were adhered in the active carbon powder surface by HAA method. The component of Pd was homogeneously distributed on the active carbon surface.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.673-678
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• 2010

In the present study, mixed carbon-supported platinum(Pt) nanoparticles were prepared by a chemical reduction method of Pt precursor solution on two types of carbon materials such as activated carbons(ACs) and graphite nanofibers(GNFs). Average crystalline sizes and loading levels of Pt metal particles could be controlled by changing a content of GNFs. The highest electroactivity for methanol oxidation was obtained by preparing the carbon supports having 15 wt% GNFs. Furthermore, with an increase of GNFs content from 0% to 15%, an electrical conductivity was changed from $10^{-4}S/cm$ to $10^{-1}S/cm$. By an introduction of 10 wt% GNFs additive, the electroactivity of platinum particles was enhanced, but was saturated in the case of 15 wt% GNFs contents. This was related with the fact that the electroactivity change was dependent on the electrical conductivity of mixed carbon supports and Pt particle deposition content or deposition morphology.

• Polymer(Korea)
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• v.27 no.1
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• pp.46-51
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• 2003

In this work, the electrode far fuel cell was fabricated by mixing carbon blacks with activated carbon fibers (ACFs) in order to form the proper three phase distribution, and then the change of electrode in three phase distribution was investigated. Pt loading yield with ACF content and Pt particle size were determined by AAS and XRD measurements, respectively. And the pore structures, including specific surface area ($S_{BET}$), microporosity, and pore size distribution (PSD) for each electrode were systematically investigated by BET volumetric measurement. The morphology of electrode in three phase distribution was determined by SEM. As an experimental result, it was observed that Pt loading yield was not influenced on the content of ACF. While, the electrode in three phase distribution was largely improved in the case of 30% ACF addition on carbon blacks. These results were probably explained by the increase of the portion of micropores, resulting in increasing the active sites of catalyst.